I recently started doing test automation with Borland SilkTest Classic. Unfortunately, the collapse/expand state is stored directly in source code, which can result in many differences when comparing sources in WinMerge.
To mitigate this issue, I have implemented a PreDiffer plugin for WinMerge. It simply ignores the leading boxes when comparing the source, see the following screenshot (without plugin and with plugin).
The plugin is configured to be suggested on test files (.t) and include files (.inc).
License: Freeware. You’re free to use this plugin also in commercial environments.
The plugin was developed in Visual Basic 6. If you find bugs, please contact me at winmerge-plugin.<yyyy-mm-dd>@lockerflockig.de, where <yyyy-mm-dd> is replaced with the current date (to bypass the spam filter).